/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.search.function;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.FieldCache;

import java.io.IOException;
import java.util.Map;

/**
 * Obtains float field values from the
 * {@link org.apache.lucene.search.FieldCache} using <code>getFloats()</code>
 * and makes those values available as other numeric types, casting as needed.
 * 
 * @version $Id: FloatFieldSource.java 555343 2007-07-11 17:46:25Z hossman $
 */

public class LongFieldSource extends FieldCacheSource {
	protected FieldCache.LongParser parser;

	public LongFieldSource(String field) {
		this(field, null);
	}

	public LongFieldSource(String field, FieldCache.LongParser parser) {
		super(field);
		this.parser = parser;
	}

	@Override
	public String description() {
		return "long(" + field + ')';
	}

	public long externalToLong(String extVal) {
		return Long.parseLong(extVal);
	}

	@Override
	public DocValues getValues(Map context, IndexReader reader)
			throws IOException {
		final long[] arr = (parser == null) ? cache.getLongs(reader, field)
				: cache.getLongs(reader, field, parser);
		return new DocValues() {
			@Override
			public float floatVal(int doc) {
				return (float) arr[doc];
			}

			@Override
			public int intVal(int doc) {
				return (int) arr[doc];
			}

			@Override
			public long longVal(int doc) {
				return arr[doc];
			}

			@Override
			public double doubleVal(int doc) {
				return arr[doc];
			}

			@Override
			public String strVal(int doc) {
				return Long.toString(arr[doc]);
			}

			@Override
			public String toString(int doc) {
				return description() + '=' + longVal(doc);
			}

			@Override
			public ValueSourceScorer getRangeScorer(IndexReader reader,
					String lowerVal, String upperVal, boolean includeLower,
					boolean includeUpper) {
				long lower, upper;

				// instead of using separate comparison functions, adjust the
				// endpoints.

				if (lowerVal == null) {
					lower = Long.MIN_VALUE;
				} else {
					lower = externalToLong(lowerVal);
					if (!includeLower && lower < Long.MAX_VALUE)
						lower++;
				}

				if (upperVal == null) {
					upper = Long.MAX_VALUE;
				} else {
					upper = externalToLong(upperVal);
					if (!includeUpper && upper > Long.MIN_VALUE)
						upper--;
				}

				final long ll = lower;
				final long uu = upper;

				return new ValueSourceScorer(reader, this) {
					@Override
					public boolean matchesValue(int doc) {
						long val = arr[doc];
						// only check for deleted if it's the default value
						// if (val==0 && reader.isDeleted(doc)) return false;
						return val >= ll && val <= uu;
					}
				};
			}

		};
	}

	@Override
	public boolean equals(Object o) {
		if (o.getClass() != this.getClass())
			return false;
		LongFieldSource other = (LongFieldSource) o;
		return super.equals(other)
				&& (this.parser == null ? other.parser == null : this.parser
						.getClass() == other.parser.getClass());
	}

	@Override
	public int hashCode() {
		int h = parser == null ? this.getClass().hashCode() : parser.getClass()
				.hashCode();
		h += super.hashCode();
		return h;
	}

}
